Shinichiro Sakata

The Conflicting Evidence of Three-dimensional Displays in Laparoscopy: A Review of Systems Old and New.

Objective:To describe studies evaluating 3 generations of three-dimensional (3D) displays over the course of 20 years. Summary Background Data:Most previous studies have analyzed performance differences during 3D and two-dimensional (2D) laparoscopy without using appropriate controls that equated conditions in all respects except for 3D or 2D viewing. Methods:Databases search consisted of MEDLINE and PubMed. The reference lists for all relevant articles were also reviewed for additional articles. The search strategy employed the use of keywords “3D,” “Laparoscopic,” “Laparoscopy,” “Performance,” “Education,” “Learning,” and “Surgery” in appropriate combinations. Results:Our current understanding of the performance metrics between 3D and 2D laparoscopy is mostly from the research with flawed study designs. This review has been written in a qualitative style to explain in detail how prior research has underestimated the potential benefit of 3D displays and the improvements that must be made in future experiments comparing 3D and 2D displays to better determine any advantage of using one display or the other. Conclusions:Individual laparoscopic performance in 3D may be affected by a multitude of factors. It is crucial for studies to measure participant stereoscopic ability, control for system crosstalk, and use validated measures of performance.

Extensive necrotising fasciitis in a 4-day-old neonate: a successful outcome from modern dressings, intensive care and early surgical intervention

Necrotising fasciitis (NF) is a fulminant and life-threatening soft tissue infection, which leads to vascular thrombosis and cutaneous ischemia. We present our experience with extensive necrotising fasciitis in a 4-day-old neonate and stress the importance of early diagnosis, modern dressings including negative pressure therapy, prompt surgical debridement and intensive care to improve the survival and cosmetic outcome of children with NF.

The impact of three-dimensional imaging on polyp detection during colonoscopy: a proof of concept study

Failures in lesion detection at colonoscopy deliver imperfect protection against colorectal cancer. Minimally elevated lesions are more likely to contain high-grade dysplasia or invasive carcinoma, but are frequently undetected during conventional two-dimensional (2D) colonoscopy. We performed a randomised, complete, across-subjects counterbalanced study of 3D versus 2D imaging for lesion detection during simulated colonoscopy in a simulation laboratory. Thirty-six gastroenterology fellows, comprising 50% of the nationwide pool in Australia, were tested on their ability to detect a 1 mm lesion that was similar in colour and surface texture to its surroundings in 20 simulated colonoscopy withdrawal videos, half of which contained a lesion and the other half were lesion-free. Testing difficulty was maximised to accommodate for ceiling effects, and experimental validity was confirmed by pilot testing using international experts in colonoscopy. We found a 25.1% absolute improvement in detection rates for 3D over 2D imaging. The sensitivity of 3D viewing was approximately twice that of 2D, and the false-positive rates with both technologies were not significantly different. This is the first study to highlight the large and immediate impact of 3D displays in the colonoscopic detection of diminutive, minimally elevated lesions, and the significant potential for the application of 3D technology to colonoscopy. Minimally elevated or depressed lesions that are more likely to contain high-grade dysplasia or invasive …

Are we burying our heads in the sand? Preventing small bowel obstruction from the V‐loc® suture in laparoscopic ventral rectopexy

There have been increasing reports in the literature highlighting the complication of V‐loc® associated small bowel obstruction in patients after laparoscopic ventral rectopexy.

Impact of simulated three-dimensional perception on precision of depth judgements, technical performance and perceived workload in laparoscopy

This study compared precision of depth judgements, technical performance and workload using two‐dimensional (2D) and three‐dimensional (3D) laparoscopic displays across different viewing distances. It also compared the accuracy of 3D displays with natural viewing, along with the relationship between stereoacuity and 3D laparoscopic performance.

The viewpoint-specific failure of modern 3D displays in laparoscopic surgery

PurposeSurgeons conventionally assume the optimal viewing position during 3D laparoscopic surgery and may not be aware of the potential hazards to team members positioned across different suboptimal viewing positions. The first aim of this study was to map the viewing positions within a standard operating theatre where individuals may experience visual ghosting (i.e. double vision images) from crosstalk. The second aim was to characterize the standard viewing positions adopted by instrument nurses and surgical assistants during laparoscopic pelvic surgery and report the associated levels of visual ghosting and discomfort.MethodsIn experiment 1, 15 participants viewed a laparoscopic 3D display from 176 different viewing positions around the screen. In experiment 2, 12 participants (randomly assigned to four clinically relevant viewing positions) viewed laparoscopic suturing in a simulation laboratory. In both experiments, we measured the intensity of visual ghosting. In experiment 2, participants also completed the Simulator Sickness Questionnaire.ResultsWe mapped locations within the dimensions of a standard operating theatre at which visual ghosting may result during 3D laparoscopy. Head height relative to the bottom of the image and large horizontal eccentricities away from the surface normal were important contributors to high levels of visual ghosting. Conventional viewing positions adopted by instrument nurses yielded high levels of visual ghosting and severe discomfort.ConclusionsThe conventional viewing positions adopted by surgical team members during laparoscopic pelvic operations are suboptimal for viewing 3D laparoscopic displays, and even short periods of viewing can yield high levels of discomfort.

Optical diagnosis of colorectal neoplasia: A Western perspective

Optical diagnosis is an emerging paradigm in Western endoscopic practice for the colonoscopic management of diminutive polyps, and includes two complementary clinical strategies: ‘resect and discard’, in which diminutive high‐confidence adenomas are identified, and then removed and discarded without pathological assessment; and ‘diagnose and leave’, where diminutive high‐confidence hyperplastic polyps are identified in the rectosigmoid and then left without resection or biopsy. Like other aspects of colonoscopy performance, adoption of optical diagnosis in Western practice is limited by operator dependency and variation in clinical effectiveness. There is substantial potential for optical diagnosis of colorectal neoplasia during colonoscopy to alleviate the rising costs of health care in the West. However, operator dependence in diagnostic performance together with critical system factors such as informed consent, credentialing, medical legal support and reimbursement incentives must be overcome before optical diagnosis of diminutive lesions is considered for widespread adoption in Western clinical practice.

Techniques for terminal ileal intubation at colonoscopy when standard maneuvers fail

Intubation of the terminal ileum is an essential component of diagnostic colonoscopy performed for symptomatic indications, such as diarrhea or suspected Crohn’s disease ( 1 ). Although not typically required for screening colonoscopy where it has limited diagnostic yield, intubation of the ileum is a defi nitive marker of complete colonoscopy, especially when there is uncertainty about cecal intubation ( 1–3 ). Stringent verifi cation of colonoscopy completion is critical for quality assurance and interval cancer prevention ( 2,4 ). Terminal ileal intubation can be diffi cult ( 1 ). Our standard technique is described in the online supplement. Th e standard maneuvers for intubation are usually eff ective; however, an ileal orifi ce (IO) that is acutely angulated can be diffi cult to identify in the forward view. Standard maneuvers can lead to unsuccessful, blind attempts at withdrawing the colonoscope tip along the cecal wall ( Supplementary video ). Here we describe techniques for ileal intubation when other maneuvers have failed: retrofl exion with or without catheter manipulation of a closed IO ( 5 ). Techniques for Terminal Ileal Intubation at Colonoscopy When Standard Maneuvers Fail

The impact of crosstalk on three-dimensional laparoscopic performance and workload

This is the first study to explore the effects of crosstalk from 3D laparoscopic displays on technical performance and workload. We studied crosstalk at magnitudes that may have been tolerated during laparoscopic surgery. Participants were 36 voluntary doctors. To minimize floor effects, participants completed their surgery rotations, and a laparoscopic suturing course for surgical trainees. We used a counterbalanced, within-subjects design in which participants were randomly assigned to complete laparoscopic tasks in one of six unique testing sequences. In a simulation laboratory, participants were randomly assigned to complete laparoscopic ‘navigation in space’ and suturing tasks in three viewing conditions: 2D, 3D without ghosting and 3D with ghosting. Participants calibrated their exposure to crosstalk as the maximum level of ghosting that they could tolerate without discomfort. The Randot® Stereotest was used to verify stereoacuity. The study performance metric was time to completion. The NASA TLX was used to measure workload. Normal threshold stereoacuity (40-20 second of arc) was verified in all participants. Comparing optimal 3D with 2D viewing conditions, mean performance times were 2.8 and 1.6 times faster in laparoscopic navigation in space and suturing tasks respectively (p< .001). Comparing optimal 3D with suboptimal 3D viewing conditions, mean performance times were 2.9 times faster in both tasks (p< .001). Mean workload in 2D was 1.5 and 1.3 times greater than in optimal 3D viewing, for navigation in space and suturing tasks respectively (p< .001). Mean workload associated with suboptimal 3D was 1.3 times greater than optimal 3D in both laparoscopic tasks (p< .001). There was no significant relationship between the magnitude of ghosting score, laparoscopic performance and workload. Our findings highlight the advantages of 3D displays when used optimally, and their shortcomings when used sub-optimally, on both laparoscopic performance and workload.

Measurement Bias of Polyp Size at Colonoscopy

BACKGROUND: The success of current and proposed strategies to reduce colorectal cancer (CRC) incidence and mortality rates are fundamentally based on measurement accuracy. OBJECTIVE: The aim of this study was to evaluate the densities of colorectal polyps individually measured at colonoscopy and whether measurement bias is a systemic phenomenon among colonoscopists. DESIGN: A population-wide, observational study. SETTING: All hospitals of the government-funded health system in Brisbane, Australia. PATIENTS: Our study investigated measurement bias at colonoscopy through systematic analysis of 8,591 individual polyp measurements recorded from 12,597 colonoscopies. All colonoscopies performed over a 12-month period between December 1, 2014, and November 30, 2015, were included. RESULTS: A total of 12,597 electronic colonoscopy reports were individually reviewed, hospital-by-hospital, and 8,591 individual size measurements from 18,276 detected polyps (47%) were obtained. LIMITATIONS: Our study is limited because the true size of unresected polyps was unknown. We chose not to compare pathologic and histologic sizes as resection specimens sent to pathologists are morphologically different and are measured differently to the pre-resection polyp images seen by endoscopists. CONCLUSIONS: Colonoscopists may be inaccurate in the measurement of polyp size and appear biased towards and against certain size measurements. These findings cast doubt over the validity of international post-polypectomy surveillance guidelines and the safety of optical diagnosis as a potential management paradigm for diminutive colorectal polyps. They also question the historical accuracy of polyp size data and risk estimates upon which these strategies were based.